As Republicans began making their case for President Bush’s re-election at the convention yesterday, their Democratic counterparts continued their aggressive efforts to characterize the Bush presidency as a failure.

In back-to-back news conferences, high-ranking Democrats, ranging from Rep. Charles Rangel to City Council Speaker Gifford Miller, attacked Mr. Bush for mishandling the war in Iraq and national security.

Pegging their remarks to the GOP’s “Nation of Courage” theme for the day, the Democrats ridiculed the president’s morning statement that the war on terrorism was not winnable and seized upon Mr. Bush’s acknowledgement last week that he had made a “miscalculation” in forecasting conditions in postwar Iraq.

“It’s clear that the president here has miscalculated,” said retired Air Force General Merrill McPeak, “miscalculated in a headlong rush to war; miscalculated in going it alone, instead of constructing a durable and robust alliance approach; miscalculated in thinking we would be greeted with bouquets thrown at us in the streets of Baghdad; miscalculated when he landed on the USS Lincoln and declared mission accomplished.”

The attacks are part of a carefully orchestrated weeklong campaign by the Democrats to counter the steady flow of positive coverage out of Madison Square Garden. The Democrats’ campaign is using the theme “Mission Not Accomplished,” a slogan that has been infused into a new series of television commercials, stamped on T-shirts and banners, and cited in dozens of speeches to describe the Bush administration’s domestic and foreign policy.

The campaign by the Democrats, organizers say, will include two daily events, one in the morning at the “rapid response war room” just blocks from the Garden and the other at a strategically chosen site in the city. Yesterday, a group of veterans gathered in front of Grant’s Tomb, where speakers railed against Mr. Bush for using the National Guard as a backdoor draft, for stretching the military too thin, for failing to provide adequate health care services to veterans, and for not strongly condemning the recent Swift Boat Veterans for Truth advertisements, which depict Senator Kerry as a liar.

“This is a president who didn’t have the courage to serve himself in Vietnam, sent other to fight for him, and now sends others to question Senator Kerry’s valorous service,” Speaker Miller said from a podium in front of Grant’s Tomb. “He doesn’t even have the courage to come out himself and do his own dirty work. This president needs to be sent home for Texas.”

Vietnam veteran Del Sandusky, who has been traveling to battleground states to campaign for Mr. Kerry, echoed the point.

“I served with John Kerry, I served with John Kerry,” he said. “Those Twinkies on TV are spreading a pack of lies. I was with John Kerry when he won his Silver Star, his Bronze Star, and two of his three Purple Hearts and he earned every one of them.”

Mr. Rangel said he was “outraged” that Mr. Bush, who did not serve in active duty, would criticize those who had actually gone into battle. The congressman later indicated that Mr. Kerry should be more aggressive in his response to the incident.

Mr. Rangel also questioned whether getting rid of Saddam Hussein was “worth the tens of thousands of lives destroyed.”

Democrats also used yesterday to accuse the Republicans of lining up moderate speakers for the convention – including Mayor Bloomberg, former Mayor Rudolph Giuliani – to disguise the right-wing agenda of the Republican platform.

“If you look at the speakers who they will parade across the stage over the course of the next four nights, they do not agree with George Bush on most of the issues,” said the Democratic National Committee chairman, Terry McAuliffe. “George Bush does not govern from the middle. He is an extreme right-wing conservative out of the mainstream of America.”

Though Democrats touched on concerns about special interests, health care, education, and spin coming out of the Republican camp, there will undoubtedly be more on those topics in the coming days. And in the meantime, Republican delegates are crisscrossing the city, attending Broadway shows, eating at restaurants, and praising their candidate.